what they do is slip a note under the counter.so they say you only gave them £90.00 or £80.00.or slight of hand it looks like you have been given full amount.
what is know as bucket shops.
Lady Scorpio do you mean the exchange shop next to the chemist/beershop/ on main road.if yes thats a bucket shop.the only time you will get that rate is if you change £3000.or 4000. but then they will say we do not have enough euro.s for that amount and offer you a silly rate.
like said stick to just one shop that you know well. if not use the barrell shops on main road.
these bucket shops know say 5% of the people will use them.if not sure use a nation wide flex card.you get a far better rate in the end.and saves you carrying loads of cash around with you.max 300 euro;s a day.but no limit on how much you spend when paying for goods with this card.
but always take a visa card as back up.
but always check front of atms.make sure there is nothing stuck on to it.